Minor spacing adjustment

The chat tab looks a little squished down towards the bottom of the browser. This change adds two pixels to the height of the chat tab, so the spacing below "Let's Chat" appears equal to that above.

Before:
![screen shot 2013-08-14 at 3 43 01 pm](https://f.cloud.github.com/assets/92284/965066/3f6e540a-0523-11e3-9bc7-025162765e24.png)

After:
![screen shot 2013-08-14 at 3 42 49 pm](https://f.cloud.github.com/assets/92284/965072/4facfef2-0523-11e3-9504-32129354717c.png)